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Destruction of Mustard Beetle. 



Preventive measures. — All that can be done is to cut off all 

 the diseased shoots early in June, before the moths have appeared, 

 and so prevent them from increasing, and to spray in autumn 

 with arsenites. 



Destruction of Mustard Beetle. 



The Mustard Beetle (Phcedon betulae) can be materially 

 lessened by various methods. The beetles pass the winter in a 

 torpid condition in any shelter where they have been working 

 in the summer and autumn. The larvae hatch from eggs laid 

 in the spring upon various plants. The beetles which deposit 

 their eggs have frequently passed the winter in hollow stems of 

 reeds along the dykes and ditches of the district, and also com- 

 monly in the hollow mustard stocks left about in and around 

 the fields, and in the mustard stubble. They also winter in 

 mustard stacks, cracks and crevices of gates, posts, fences, 

 rough grass, and all manner of places. 



The larvae when mature pass into the ground to pupate, in 

 which stage they remain from two to three weeks ; the beetles 

 coming from these pupae at once attack the mustard plant. The 

 beetle is found practically all the summer ; it is therefore pro- 

 bable that there is more than one brood every year. The eggs 

 laid in the spring are placed on all kinds of cruciferae ; the 

 larvae feed upon the leaves ; they are dull, smoky-yellow 

 creatures, slightly hairy and spotted with black, with black head 

 and six black legs ; there is also a distinct caudal foot and a 

 row of curious tubercles along each side from which can be 

 protruded curious yellow glands ; when mature they reach about 

 three-fourths of an inch. These larvae can be easily seen on the 

 leaves, and are vulnerable at this stage. 



Preventive and Remedial Measures. 



All precautions should be taken to destroy as much winter 

 shelter as possible. After a bad attack it would be advisable to 

 burn the mustard straw, not at once, but after it has been 

 allowed to stand some time in heaps in the fields ; the beetles 



